User’s Manual
C166S V1 SubSystem
Central Processing Unit
User’s Manual
3-6
V 1.6, 2001-08
Byte write operations to word wide SFRs via indirect or direct 16-bit (mem) addressing
or byte transfers via the PEC force zeros in the non-addressed byte. Byte write
operations via short 8-bit (reg) addressing can only access the low byte of an SFR and
force zeros in the high byte. It is therefore recommended, to use the bit field instructions
(BFLDL and BFLDH) to write to any number of bits in either byte of an SFR without
disturbing the non-addressed byte and the unselected bits.
Reserved Bits
Some of the bits which are contained in the C166S’s SFRs are marked as Reserved.
User software should never write 1s to reserved bits. These bits are currently not
implemented and may be used in future products to invoke new functions. In this case,
the active state for these functions will be 1, and the inactive state will be 0. Therefore
writing only 0s to reserved locations provides portability of the current software to future
devices. After read accesses reserved bits should be ignored or masked out.
Содержание C166S V1 SubSystem
Страница 10: ...User s Manual C166S V1 SubSystem User s Manual I 6 V 1 6 2001 08...
Страница 16: ...User s Manual C166S V1 SubSystem Introduction User s Manual 1 6 V 1 6 2001 08...
Страница 126: ...User s Manual C166S V1 SubSystem Central Processing Unit User s Manual 3 96 V 1 6 2001 08...
Страница 178: ...User s Manual C166S V1 SubSystem Memory Organization User s Manual 4 52 V 1 6 2001 08...
Страница 206: ...User s Manual C166S V1 SubSystem Instruction Set User s Manual 5 28 V 1 6 2001 08...
Страница 306: ...User s Manual C166S V1 SubSystem Detailed Instruction Set User s Manual 6 100 V 1 6 2001 08...
Страница 362: ...User s Manual C166S V1 SubSystem The External Bus Interface User s Manual 8 40 V 1 6 2001 08...
Страница 452: ...User s Manual C166S V1 SubSystem General Purpose Timer Unit User s Manual 12 44 V 1 6 2001 08...
Страница 454: ...User s Manual C166S V1 SubSystem Instruction Index User s Manual 13 2 V 1 6 2001 08...
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